1. Field of the Invention
The present invention relates to a treadmill as a kind of indoor sporting goods, and more particularly, to a treadmill having a walking belt whose running speed is automatically adjusted in conformity with the walking or running speed of a user, without any manipulation of a walking belt speed control button, and a method for automatically adjusting the running speed of a walking belt in a treadmill.
2. Discussion of Related Art
Generally, a treadmill as indoor sporting goods is widely spread. As well known, the treadmill allows a user to walk or lightly run on a walking belt moving in a forward direction. The advantages obtained by using the treadmill are as follows: firstly, the exercise on the treadmill is taken even in a small area; and secondly, the obtained effect from the exercise on the treadmill is influenced to the whole body of the user. Because of such advantages, the number of persons using treadmill has been gradually increased.
When the user desires to walk or run at a faster or slower speed during walking or running on the walking belt, however, the user should accelerate or decelerate the running speed of the walking belt in conformity with the desired speed. In this case, there occurs an inconvenience that even during he walks or runs, he has to adjust the walking belt speed control button on the instrument panel.
If the user walks or runs at the faster speed in the state where the walking belt speed control button on the instrument panel has not been adjusted, his body moves forward and is then adjacent to the instrument panel (that is, the foremost front of the treadmill), such that he can not further walk on the walking belt. To the contrary, if he walks or runs at the slower speed in the state where the walking belt speed control button on the instrument panel has not been adjusted, his body moves backward and is then adjacent to the last rear portion of the treadmill, such that he can not further walk on the walking belt.
Accordingly, the present invention is directed to a treadmill having a walking belt whose running speed is automatically adjusted that substantially obviates one or more of the problems due to limitations and disadvantages of the related arts.
An object of the invention is to provide a treadmill having a walking belt whose running speed is automatically adjusted in conformity with the walking or running speed of a user, without any manipulation of a walking belt speed control button, when he walks or runs at faster or slower speed than a while ago, and a method for automatically adjusting the running speed of a walking belt in a treadmill.
To accomplish this and other objects of the present invention, a treadmill according to the present invention comprises an encoder for checking the rotation speed of a motor, and an electric current detecting sensor for detecting the load of the motor. The encoder and the electric current detecting sensor act as a motor driving unit, which checks even a minor change in the rotation speed or load of the motor caused by a user who walks or runs on a walking belt, determines the necessity of increasing or decreasing the rotation speed of the motor, and increase or decrease the rotation speed of the motor in a very short time that the user may not realize.
When the walking belt of the treadmill is driven by the activation of the motor, the rotation speed of the motor is varied momentarily in accordance with the weight and motion speed of the user during walking or running on the walking belt. Let""s assume that the motor rotates at 400 rpm in the state where the user is not positioned on the walking belt. If the user is positioned on the walking belt, the rotation speed of the motor is reduced momentarily to, for example, 200-350 rpm, depending upon his weight. Then, after a predetermined time elapses, the rotation speed thereof is again kept at 400 rpm.
According to the present invention, the treadmill is capable of increasing or decreasing the running speed of the motor by sensing the fact that the walking or running speed of the user does not correspond with the running speed of the walking belt. During the user runs on the walking belt at the corresponding speed to a constant running speed of about 8 km/hr or more of the walking belt, if he runs at a slower speed, the running speed of the walking belt is faster than the running speed of the user and thereby, the body of the user moves backward. At this time, the user""s foot moving forward functions as a brake when stepping on the walking belt, such that the running speed of the walking belt can be decreased. This causes the rotation speed of the motor to be reduced. If the rotation speed of the motor is reduced to a lowest allowable value of an initial set value, the encoder feedback from the motor is checked to thereby re-adjust the set value.
On the other hand, during the user runs on the walking belt if he runs at a faster speed, the running speed of the walking belt increases temporarily. This means the principles that the user adds a driving force to his feet placed on the ground, thereby advancing forward. If the above principles are applied on the walking belt during rotation, the current speed of the walking belt increases by the driving force of the user""s feet placed on the ground. This causes the rotation speed of the motor to increase. If the rotation speed of the motor increases a highest allowable value of the initial set value, the encoder feedback from the motor is checked to re-adjust the set value.
Moreover, according to the present invention, the treadmill is capable of increasing or decreasing the running speed of the motor by sensing the fact that the user moves from his original position to the front or back regions of the walking belt. As previously discussed, if the user walks or runs at the faster speed than the set running speed of the walking belt, he is deviated from his original position to advance forward. Contrarily, if the user walks or runs at the slower speed than the set running speed of the walking belt, he is deviated from his original position to advance backward. The deviation of the user from the original position means that the walking or running speed of the user increases or decreases. Therefore, it is checked whether the user is deviated from his original position, and in accordance with the checked result, the rotation speed of the motor increases or decreases. As a result, the rotation speed of the motor can be adjusted in conformity with the walking or running speed of the user.
On the basis of the above discussion, the treadmill according to the present invention first checks and determines whether the rotation speed of the motor is deviated from an initial set range or the user is deviated from his original position and then if only one of the two deviations is checked, automatically increase or decrease the rotation speed of the motor.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.